The bowl section of a urinal may be flushed with water in order to flush foreign matter such as urine and hair attached to the bowl surface and to replace the seal water in the trap by newly supplied water. Passing water in the bowl section of the urinal for the purpose of flushing foreign matter and replacing seal water requires passing a large amount of water along the bowl surface. The water flowing along the bowl surface is less likely to splash out of the bowl section. The user standing before the urinal during bowl flush is rarely wetted. The flush sound at the time of bowl flush is small.
However, the odor of the urinal may fail to be sufficiently removed by only flushing the bowl section of the urinal with water. Thus, several deodorization techniques for removing the odor of the urinal have been proposed. One of such deodorization techniques is a urinal in which water does not flow down along the vertical surface of the toilet bowl, but is directly squirted from a water jetting hole through a water supply pipe (Patent Literature 1 (Japanese Unexamined Utility Model Application Publication No. S62-94173)). In the urinal disclosed in Patent Literature 1, water is sprinkled to the space in the bowl section of the urinal.
Water is sprinkled to the space in the bowl section of the urinal through e.g. the sprinkling hole of a sprinkling device. The flow velocity of water significantly changes near the sprinkling hole by pressure increase of water and pressure release in the space. The water is sprinkled at a fixed pressure from the sprinkling hole having a small diameter. Thus, the flow velocity of water significantly changes near the sprinkling hole. The change of flow velocity of water may induce what is called a shower sound, or a drop sound when the droplet of water is brought into contact with the bowl section.
In the urinal disclosed in Patent Literature 1, water may be sprinkled before or during the act of urination of the user of the urinal apparatus. Then, the user may hear a shower sound or drop sound. This causes a problem of giving discomfort to the user. For instance, before the act of urination, the user may stop approaching the urinal apparatus and abort the act intended for urination. Alternatively, during urination, the user may miss the target, and urine may be splashed out of the bowl section.
The water supplied to the urinal may utilize tap water suitable for drinking. On the other hand, the supplied water may utilize miscellaneous water originating from used tap water (sewage), or miscellaneous water originating from rain water. The water quality management of miscellaneous water (e.g., “graywater”) may be minimized compared with tap water. Thus, miscellaneous water may contain a relatively large amount of organic substances. If miscellaneous water contains a large amount of organic substances, bacteria and microorganisms nourished by the organic substances may multiply and produce an aggregation in conjunction with products therefrom. The aggregation of bacteria and microorganisms in conjunction with products therefrom is called e.g. biofilm.
For instance, when miscellaneous water is sprinkled in the urinal disclosed in Patent Literature 1, the water jetting hole may be clogged by the production of biofilm. When the water jetting hole is clogged, the sprinkled water may have an unstable direction and fail to be sprinkled to a desired space. This causes a problem of decreased level of suppressing odor generated from the urinal and soil generated in the urinal.